JPH0640759U - Heat storage type heating device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent deterioration of heat conduction and heat transfer of each part due to cracking of heat storage material. [Structure] The heat storage body 11 is placed in a heat transfer container 12 to form a solid heat storage material 1
3 and a substance 14 that becomes a liquid in the heat storage temperature range are housed and formed. Further, a substance containing magnesia as a main component can be used as the solid heat storage material 13, and a mixture of sodium nitrate, sodium nitrite, and potassium nitrate can be used as the substance 14 that becomes a liquid in the heat storage temperature range. it can. [Effect] Solid heat storage material 1 by repeated thermal expansion and contraction
Even if a crack occurs in the crack 3, the liquid 14 having good thermal conductivity enters the crack, so that the effective thermal conductivity of the heat storage body 11, heat transfer between the electric heater 3 and the heat storage body 11, and the heat storage body 11. The heat transfer between the air 8 can be prevented from decreasing with time, and the heating output of the heat storage type heating device 1 and the like can be prevented from decreasing with time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a heat storage type heating device, and more particularly to a heat storage type heating device in which a heating heat load per unit volume of a heat storage body is large and which is small and compact.

[0002]

[Prior art]

 FIG. 2 shows an example of a conventional heat storage type heating device using nighttime electric power. As shown in the figure, the heat storage type heating device 1 stores a heat storage body 2 in a container 6 kept warm by a heat insulating material, heats the heat storage body 2 by an electric heater 3, and stores heat in the heat storage body 2. When heating is required, the blower 4 is driven to supply the air 8 to the surface of the heat storage body 2, and the air 8 is heated by the heat exchange between the air 8 and the heat storage body 2, and is taken as warm air 9 to the outside of the device. It is known that it was put out. Further, in response to a demand change for the heating demand, the opening of the air volume adjustment damper 5 is adjusted to change the air volume of the warm air 9 to respond. A magnesia longa is mainly used for the heat storage body 2 of such a conventional heat storage type heating device 1.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional technique, sufficient consideration is not given to cracking of the heat storage body 2 due to repeated thermal expansion and contraction, and therefore there are the following problems. For example, the heat storage body 2 is heated to 500 to 700 ° C. at the time of heat input and cooled to room temperature to 300 ° C. at the time of heat radiation. When the heat storage body 2 is magnesia brick, the heat storage body undergoes thermal expansion of 0.1 to 0.2% per 100 ° C. Therefore, if rapid heating or cooling is performed, the heat storage body 2 may be cracked due to thermal reaction. There is. Due to this crack, when an air layer is formed on the surface or inside of the heat storage body 2, the effective thermal conductivity of the heat storage body 2 itself, the heat transfer between the electric heater 3 and the heat storage body 2, the heat between the heat storage body 2 and the air 8. Transmission is reduced. When the effective thermal conductivity of the heat storage body 2 itself decreases, only the surface portion of the heat storage body 2 can be used for effective heat storage. As a result, the heat input characteristic and the heat output characteristic of the entire heat storage body are deteriorated. Further, when the heat transfer between the electric heater 3 and the heat storage body 2 is reduced, the heat generated by the electric heater 3 is less likely to be transferred to the heat storage body 2, so the temperature of the electric heater 3 rises and the electric heater 3 burns out. Occurs. Further, if the heat transfer between the heat storage body 2 and the air 8 is reduced, the heat exchange efficiency between them is reduced, and it becomes difficult to take out the stored heat, so that the maximum heating output and the effective heat storage amount are reduced. Occurs. As a result, the heat output characteristic is deteriorated as a whole.

An object of the present invention is to provide a heat storage type heating device that prevents deterioration of heat conduction and heat transfer of each part due to cracking of the heat storage material.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is characterized in that a heat storage body is formed by housing a solid heat storage material and a substance that becomes a liquid in a heat storage temperature range in a heat transfer container.

A substance containing magnesia as a main component can be used as the solid heat storage material.

As the substance that becomes a liquid in the heat storage temperature range, a mixture of sodium nitrate, sodium nitrite, and potassium nitrate can be used.

[0008]

[Action]

 With this configuration, according to the present invention, the above object can be achieved by the following actions. When a solid heat storage material cracks during use due to thermal stress, a substance that becomes liquid in the heat storage temperature range enters this crack. As a result, the air phase does not occur in the cracks, so that the effective thermal conductivity of the heat storage body can be prevented from lowering, and the heat transfer between the heat storage body and the heat source and between the heat storage body and the heated fluid can be prevented. Therefore, it is possible to prevent the heating output from decreasing with time. When the substance that becomes liquid in the heat storage temperature range is a mixture of sodium nitrate, sodium nitrite, and potassium nitrate, the thermal conductivity is high, so the effective thermal conductivity of the heat storage body itself can be kept high.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional configuration of an embodiment of the present invention. In this embodiment, only the structure of the heat storage body is different from that of the conventional example shown in FIG. 2. Therefore, parts having the same functions or configurations as those of the conventional example are designated by the same reference numerals and description thereof will be omitted. As shown in the figure, the heat storage body 11 includes a solid heat storage material 13 in the form of granules and / or powder in a heat transfer container 12 having heat resistance and heat conductivity, and a substance that becomes a liquid in a heat storage temperature range (hereinafter, referred to as liquid 14) and 14 are filled. As the solid heat storage material 13, for example, magnesia or alumina is suitable because it is desirable that the specific heat per unit volume is high, the thermal conductivity is high, the heat resistance is excellent, and the cost is low. In this embodiment, a magnesia clinker is used. The liquid 14 preferably has a high specific heat per unit volume, a high thermal conductivity, a low viscosity, and an excellent heat resistance. Therefore, for example, sodium nitrate (0 to 10%) and nitrous acid are used. A mixture of sodium (40-50%) and potassium nitrate (40-50%) is suitable. In this example, a mixture of 7% sodium nitrate, 49% sodium nitrite and 44% potassium nitrate is used. The mixture solidifies at 142 ° C or lower, but is liquid at or above that temperature. Further, although only one heat storage body 11 is shown in FIG. 1, it is divided into a plurality of pieces as needed and stored as in the conventional case.

The operation of the embodiment thus configured will be described below. When the heat storage body 11 is heated by the electric heater 3, the liquid 14 is liquefied and the solid heat storage body 13 is heated, and heat is stored in them. When heating is used, the blower 4 is operated to suck in the air 8 which is the fluid to be heated, and the air 8 is caused to flow through the flow path formed around the heat storage body 11 to heat it, and the air is adjusted via the air volume adjustment damper 5. It is supplied to the outside as wind 9. By repeating the above heating and heat exchange, the heat storage body 11 is heated and cooled, and due to the repeated thermal expansion and contraction, cracks occur as in the conventional case. However, since the liquid 14 enters the cracks and no air layer is generated, the effective thermal conductivity of the heat storage body 11 is reduced, the heat transfer between the electric heater 3 and the heat storage body 11 is reduced, and the space between the heat storage body 11 and the air 8 is reduced. The phenomenon such as the decrease in heat transfer does not occur. Therefore, the phenomenon that the heat output decreases with time as seen in the conventional device does not occur.

A comparison of heating characteristics between the above-described embodiment and the conventional heat storage type heating device will be described with reference to FIGS. 3 and 4. FIG. 3 shows the transition of the heating heat quantity according to the number of times of heat storage in the above-mentioned embodiment and the conventional example. When heat is input to the heat storage body while keeping the surface temperature of the electric heater 3 at 600 ° C. so that the electric heater 3 does not burn out, in the conventional device, when the number of heat storage increases, as described above, the electric heater 3 and the heat storage material 2 are separated from each other. It has been observed that the heat transfer is reduced and the temperature of the electric heater 3 is excessively increased, so that the heat input time is shortened and the heat input amount, that is, the heating heat amount is reduced. On the other hand, in the device of this example, it was not necessary to shorten the heat input time, and the heating heat quantity did not decrease.

FIG. 4 shows the transition of the air temperature difference between the inlet and the outlet of the heating device immediately after the completion of heat input in this embodiment and the conventional device. The air temperature difference between the inlet and the outlet of the heating device rapidly decreased in the conventional heat storage heating device, but no change was observed in the device of the present embodiment.

[0013]

[Effect of device]

 As described above, according to the present invention, even if a crack occurs in the solid heat storage material due to repeated thermal expansion and contraction, a liquid having good thermal conductivity enters into the crack, so that It is possible to prevent the effective heat conductivity, the heat transfer between the electric heater and the heat storage body, and the heat transfer between the heat storage body and the air from decreasing with time, and to prevent the heating output of the heat storage type heating device from decreasing with time. effective.

As a result, since it is not necessary to expect the heating heat quantity to decrease with time, the heating heat quantity per unit volume of the heat storage body can be made larger than in the conventional case, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional configuration of a heat storage type heating device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional configuration of a conventional heat storage type heating device.

FIG. 3 is an example showing a comparison between an example of the present invention and a conventional example regarding heat storage characteristics.

FIG. 4 is an example showing a comparison between an example of the present invention and a conventional example regarding heat storage characteristics.

[Explanation of symbols]

 1 Heat Storage Type Heating Device 2 Heat Storage Material 3 Electric Heater 4 Blower 5 Air Volume Adjustment Damper 6 Heat Retaining Container 11 Heat Storage Body 12 Heat Transfer Container 13 Solid Heat Storage Material 14 Liquid

Front page continuation (72) Fumio Yoshiya 4-33 Komachi, Naka-ku, Hiroshima City, Hiroshima Prefecture Sales Department, Chugoku Electric Power Co., Inc. (72) Tetsuyoshi Ishida 3-36 Takaramachi, Kure City, Hiroshima Prefecture Babcock Hitachi Kure Research In-house (72) Hidenori Hidaka, No. 36, Takara-cho, Kure-shi, Hiroshima, Babcock-Hitachi Co., Ltd., Kure Laboratory (72) In-house creator, Takeo Takataka 6-9, Takara-cho, Kure-shi, Hiroshima, Babcock-Hitachi, Kure Plant ( 72) Inventor Yu Morikawa 6-9 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Kure Factory (72) Inventor Tadayuki Fujiwara 2-6-2 Otemachi, Chiyoda-ku, Tokyo Babcock Hitachi Ltd.

Claims (3)

[Scope of utility model registration request] 1. A heat storage body, a heating source for heating the heat storage body, the heat storage body and the heating source are housed, and a flow path is formed on the surface of the heat storage tank for passing a fluid to be heated. In a heat storage type heating device including a heat retention container, the heat storage body is formed by accommodating a solid heat storage material and a substance that becomes a liquid in a heat storage temperature region in a heat transfer container. apparatus. 2. The solid heat storage material according to claim 1,
A heat storage type heating device characterized by being a substance whose main component is magnesia. 3. The heat storage type heating device according to claim 1, wherein the substance that becomes a liquid in the heat storage temperature range is a mixture of sodium nitrate, sodium nitrite, and potassium nitrate.